U.S. patent number 5,683,312 [Application Number 08/615,346] was granted by the patent office on 1997-11-04 for fluid or liquid filled non-wound golf ball.
This patent grant is currently assigned to Acushnet Company. Invention is credited to Herbert C. Boehm, Christopher Cavallaro, Kevin M. Harris, William E. Morgan, Samuel A. Pasqua, Jr., Walter L. Reid.
United States Patent |
5,683,312 |
Boehm , et al. |
November 4, 1997 |
Fluid or liquid filled non-wound golf ball
Abstract
A golf ball having a diameter of approximately 1.68 to 1.90
inches and comprising: a fluid mass at the center of the ball; a
first, solid, non-wound mantle layer surrounding the fluid mass
comprised of a polymer material selected from the group of
thermoset rubber material, thermoplastic elastomeric material and
plastic and having an inner diameter in the range of 30 to 70% of
the ball diameter; a second, solid, non-wound mantle layer
surrounding and abutting the first mantle layer and being a polymer
material selected from the group of thermoset rubber material and
thermoplastic elastomeric material and having an outer diameter in
the range of 80 to 98% of the ball diameter, a hardness of
approximately 30 to 95 Shore C and a resiliency greater than 40
bashore; and a cover surrounding the second mantle layer.
Inventors: |
Boehm; Herbert C. (Norwell,
MA), Morgan; William E. (Barrington, RI), Reid; Walter
L. (Mattapoisett, MA), Pasqua, Jr.; Samuel A. (Bristol,
RI), Cavallaro; Christopher (Attleboro, MA), Harris;
Kevin M. (New Bedford, MA) |
Assignee: |
Acushnet Company (Fairhaven,
MA)
|
Family
ID: |
24464965 |
Appl.
No.: |
08/615,346 |
Filed: |
March 11, 1996 |
Current U.S.
Class: |
473/354; 473/376;
473/378 |
Current CPC
Class: |
A63B
37/0003 (20130101); B29C 43/027 (20130101); B29C
43/146 (20130101); A63B 37/0039 (20130101); A63B
37/0052 (20130101); A63B 37/0076 (20130101); A63B
37/0096 (20130101); A63B 37/08 (20130101); A63B
2037/085 (20130101); A63B 2037/087 (20130101); B29C
33/0022 (20130101); B29C 2043/023 (20130101); B29K
2009/06 (20130101); B29K 2021/00 (20130101); B29L
2031/54 (20130101); B29L 2031/545 (20130101) |
Current International
Class: |
A63B
37/00 (20060101); B29C 43/02 (20060101); B29C
43/14 (20060101); A63B 37/08 (20060101); A63B
37/02 (20060101); A63B 037/08 () |
Field of
Search: |
;473/354,377,376,378 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Marlo; George J.
Attorney, Agent or Firm: Pennie & Edmonds LLP
Claims
We claim:
1. A golf ball having a diameter and being comprised of a core and
a cover, wherein the core is further comprised of a fluid mass at
the center of the ball, a first mantle layer surrounding the fluid
mass and a second, solid, non-wound mantle layer surrounding and
abutting the first mantle layer, wherein the first mantle layer has
an inner diameter of 30 to 70% of the ball diameter and is a
polymer material selected from the group of thermoset rubber,
plastic, and thermoplastic elastomeric material and the second
mantle layer has an outer diameter of 80 to 98% of the ball
diameter and the second mantle layer is a polymer material selected
from the group of thermoset rubber materials and thermoplastic
elastomeric materials.
2. The golf ball of claim 1 wherein the golf ball diameter is at
least 1.68 inches.
3. The golf ball of claim 1 wherein the cover is comprised of a
polymer selected from the group of ethylene, propylene, butene-1
and hexane-1 based monomers.
4. The golf ball of claim 1, wherein the cover is comprised of a
material selected from the group of polyether and polyester
thermoplastic urethane, thermoset polyurethane, ionomer resins, low
modulus ionomers, high modulus ionomers and blends thereof.
5. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the first mantle layer has an inner
diameter of approximately 0.5 to 1.18 inches.
6. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the first mantle layer has an inner
diameter of approximately 0.75 to 1.1 inches.
7. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches the first mantle layer has an inner
diameter of approximately 0.9 to 0.95 inches.
8. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the second mantle layer has an inner
diameter of approximately 0.55 to 1.45 inches.
9. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the second mantle layer has an inner
diameter of approximately 0.8 to 1.3 inches.
10. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the second mantle layer has an outer
diameter of approximately 1.3 to 1.65 inches.
11. The golf ball of claim 1 wherein the golf ball diameter is
approximately 1.68 inches and the second mantle layer has an outer
diameter of approximately 1.45 to 1.62 inches.
12. The golf ball of claim 1 wherein the second mantle layer is
comprised of more than one layer.
13. The golf ball of claim 1 wherein the fluid has a specific
gravity of greater than 1.2 and a viscosity of less than or equal
to 100 cps.
14. The golf ball of claim 1 wherein the fluid has a specific
gravity of approximately 1.3 to 1.55 and a viscosity of less than
or equal to 10 cps.
15. The golf ball of claim 1 wherein the fluid has a specific
gravity of less than or equal to 1.2 and a viscosity greater than
100 cps.
16. The golf ball of claim 1 wherein the fluid has a specific
gravity of approximately 1.15 to 1.2 and a viscosity of
approximately 100 to 1500 cps.
17. The golf ball of claim 16 wherein the fluid has a viscosity of
approximately 500 cps.
18. A golf ball having a diameter of approximately 1.68 to 1.90
inches and comprising:
a fluid mass at the center of the ball;
a first, solid, non-wound mantle layer surrounding the fluid mass
comprised of a polymer material selected from the group of
thermoset rubber material, thermoplastic elastomeric material and
plastic and having an inner diameter in the range of 30 to 70% of
the ball diameter;
a second, solid, non-wound mantle layer surrounding and abutting
the first mantle layer and being a polymer material selected from
the group of thermoset rubber material and thermoplastic
elastomeric material and having an outer diameter in the range of
80 to 98% of the ball diameter, a hardness of approximately 30 to
95 Shore C and a resiliency greater than 40 bashore; and
a cover surrounding the second mantle layer.
19. The golf ball of claim 18 wherein the cover is comprised of a
material selected from the group of ethylene, propylene, butene-1
and hexane-1 based homopolymers and copolymers.
20. The golf ball of claim 18, wherein the cover is comprised of a
material selected from the group of polyether and polyester
thermoplastic urethane, thermoset polyurethane, ionomer resins, low
modulus ionomers, high modulus ionomers and blends thereof.
Description
FIELD OF THE INVENTION
The present invention is directed to a golf ball and, more
particularly, a golf ball comprised of a fluid or liquid center, a
first mantle layer surrounding the center, a second, solid,
non-wound mantle layer and a cover.
BACKGROUND OF THE INVENTION
Generally, golf balls have been classified as two piece balls or
three piece balls. Two piece balls are comprised of a solid
polymeric core and a cover. These balls are generally easy to
manufacture, but are regarded as having limited playing
characteristics. Three piece balls are comprised of a solid or
liquid filled center surrounded by tensioned elastomeric material
and a cover. Three piece balls generally have a good "click" and
"feel" when struck by a golf club, but are more difficult to
manufacture than two piece balls.
The prior art is comprised of various golf balls that have been
designed to provide optimal playing characteristics. These
characteristics are generally the initial velocity and spin of the
golf ball, which can be optimized for various players. For
instance, certain players prefer to play a ball that has a high
spin rate for playability. Other players prefer to play a ball that
has a low spin rate to maximize distance. However, these balls tend
to be hard feeling and difficult to control around the greens.
The prior art is comprised of liquid filled golf balls. Wound golf
balls have been made with liquid centers for many years. Both U.S.
Pat. Nos. 1,568,513 and 1,904,012 are directed to wound golf balls
with liquid filled centers. U.S. Pat. Nos. 5,150,906 and 5,480,155,
are directed to a hollow spherical shell of a polymeric material
which is filled with a liquid or unitary, non-cellular material
that is a liquid when introduced into the shell. The shell is
disclosed as being the outer cover or an inner layer with the outer
cover formed to the external surface thereof. The shell varies in
thickness from about 0.060 to 0.410 inches in thickness.
SUMMARY OF THE INVENTION
Broadly, the present invention comprises a golf ball having a core
and a cover in which the core is comprised of a fluid or liquid
center surrounded by a mantle portion. The mantle portion is
comprised of a first mantle layer surrounding the center and a
second, solid, non-wound mantle layer that is comprised of a
thermoset rubber or thermoplastic elastomeric material. The mantle
portion of the core, preferably, has an inner diameter in a range
of about 30 to 70% of the finished ball diameter and an outer
diameter of about 80 to 98% of the finished ball diameter.
Still further, for a preferred golf ball having an outer diameter
of approximately 1.68 inches, the first mantle layer preferably has
an inner diameter of approximately 0.5 to 1.18 inches and, more
preferably, approximately 0.75 to 1.1. Most preferably, the first
mantle layer has an inner diameter of approximately 0.9 to 0.95
inches. The present invention is also preferably comprised of a
second mantle layer having an inner diameter in the range of 0.55
to 1.45 inches and, more preferably, having an inner diameter of
approximately 0.8 to 1.3 inches. Yet further still, the present
invention has a second mantle layer having an outside diameter in
the range of 1.3 to 1.65 inches and, more preferably, in the range
of 1.45 to 1.62 inches. In the most preferred embodiment, the
second mantle layer has a radial thickness of about 0.2 to 0.3
inches.
Still further, the invention is preferably a golf ball comprised of
a fluid or liquid center; a first mantle layer comprised of either
a thermoplastic elastomer, such as a rubber based material, or a
plastic material, such as polypropylene; a second mantle layer
comprised of a thermoset rubber material, such as polyisoprene,
styrene butadiene or polybutadiene, or combinations thereof or
thermoplastic elastomeric materials such as copolymers of
methyl-methacrylate with butadiene and styrene, copolymers of
methyl-acrylate with butadiene and styrene, acrylonitrile styrene
copolymers, polyether-ester, polyether-amide, polyurethane and/or
blends thereof; and a cover.
More particularly, the invention is directed to a golf ball having
a fluid or liquid filled center having a specific gravity and
viscosity such that the performing properties of the ball, such as
the moment of inertia, may be varied to achieve certain desired
parameters such as spin rate, spin decay, compression, initial
velocity, etc. Still further the fluid filled center preferably has
a high specific gravity for a high spin ball or a low specific
gravity for a low spin ball. Still more particularly, the invention
is directed to a golf ball having a high viscosity fluid or liquid
filled center for a low spin rate ball or a low viscosity for a
high spin rate ball. By providing two mantle layers for surrounding
the center, the properties thereof, such as specific gravity,
resiliency and compression can be varied to make balls having the
desired characteristics .
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a sectional view of a ball of the present invention;
FIG. 1A is a sectional view of a ball of the present invention with
a second mantle layer having two layers;
FIG. 2 is a sectional view of a mold preforming a mantle layer
according to the present invention; and
FIG. 3 is a sectional view of the mold forming a golf ball core
according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, ball 10 includes a cover 11 and a core 12. The
core 12 in turn includes a fluid or liquid filled cavity or center
18 and a mantle portion 16, which is comprised of a first, inner
portion 20 and a second, outer portion 22.
The cover 11 provides the interface between the ball 10 and a club
and other objects such as trees, cart paths and grass. Properties
that are desirable for the cover are good flowability, high
abrasion resistance, high tear strength, high resilience, and good
mold release, among others. The cover 11 can be comprised of
polymeric materials such as ionic copolymers of ethylene and an
unsaturated monocarboxylic acid which are available under the
trademark "SURLYN" of E. I. DuPont De Nemours & Company of
Wilmington, Del. or "IOTEK" or "ESCOR" from Exxon. These are
copolymers of ethylene and methacrylic acid or acrylic acid
partially neutralized with zinc, sodium, lithium, magnesium,
potassium, calcium, manganese, nickel or the like.
In accordance with the various embodiments of the present
invention, the cover 11 is of a thickness to generally provide
sufficient strength, good performance characteristics and
durability. Preferably, the cover 11 is of a thickness from about
0.03 inches to about 0.12 inches. More preferably, the cover 11 is
about 0.04 to 0.09 inches in thickness and, most preferably, is
about 0.05 to 0.085 inches in thickness.
In accordance with a preferred embodiment of this invention, the
cover in question can be formed from mixtures or blends of zinc
and/or lithium and sodium ionic copolymers.
Surlyn resins are ionic copolymers in which sodium, lithium or zinc
salts are the reaction product of an olefin having from 2 to 8
carbon atoms and an unsaturated monocarboxylic acid having 3 to 8
carbon atoms. The carboxylic acid groups of the copolymer may be
totally or partially neutralized and might include methacrylic,
crotonic, maleic, fumaric or itaconic acid.
This invention can likewise be used in conjunction with
homopolymeric and copolymer materials such as:
(1) Vinyl resins such as those formed by the polymerization of
vinyl chloride, or by the copolymerization of vinyl chloride with
vinyl acetate, acrylic esters or vinylidene chloride.
(2) Polyolefins such as polyethylene, polypropylene, polybutylene
and copolymers such as polyethylene methylacrylate, polyethylene
ethylacrylate, polyethylene vinyl acetate, polyethylene methacrylic
or polyethylene acrylic acid of polypropylene acrylic acid and
copolymers and single-site catalytic polymers containing olefinic
monomers.
(3) Polyurethanes such as those prepared from polyols and
diisocyanates or polyisocyanates.
(4) Polyamides such as poly(hexamethylene adipamide) and others
prepared from diamines and dibasic acids, as well as those from
amino acids such as poly(caprolactam), and blends of polyamides
with Surlyn, polyethylene, ethylene copolymers,
ethyl-propylene-non-conjugated diene terpolymer, etc.
(5) Acrylic resins and blends of these resins with poly vinyl
chloride, elastomers, etc.
(6) Thermoplastic rubbers such as the urethanes, olefinic
thermoplastic rubbers such as blends of polyolefins with
ethyl-propylene-non-conjugated diene terpolymer, block copolymers
of styrene and butadiene, or isoprene or ethylene-butylene rubber,
polyether block amides, an example of such a product is sold under
the trademark "Pebax" by Rilsan Industrial, Inc., Birdsboro, Pa.
19508.
(7) Polyphenylene oxide resins, or blends of polyphenylene oxide
with high impact polystyrene as sold under the trademark "Noryl" by
General Electric Company, Pittsfield, Mass.
(8) Thermoplastic polyesters, such as polyethylene terephthalate,
polybutylene terephthalate, polyethylene terephthalate/glycol
modified and elastomers sold under the trademarks "Hytrel" by E. I.
DuPont De Nemours & Company of Wilmington, Del. and "Lomod" by
General Electric Company, Pittsfield, Mass.
(9) Blends and alloys, including polycarbonate with acrylonitrile
butadiene styrene, polybutylene terephthalate, polyethylene
terephthalate, styrene maleic anhydride, polyethylene, elastomers,
etc. and polyvinyl chloride with acrylonitrile butadiene styrene or
ethylene vinyl acetate or other elastomers. Blends of thermoplastic
rubbers with polyethylene, propylene, polyacetal, nylon,
polyesters, cellulose esters, etc.
Preferably, the cover 11 is comprised of polymers such as ethylene,
propylene, butene-1 or hexane-1 based homopolymers and copolymers
including functional monomers such as acrylic and methacrylic acid
and fully or partially neutralized ionomer resins and their blends,
methyl acrylate, methyl methacrylate homopolymers and copolymers,
imidized, amino group containing polymers, polycarbonate,
reinforced polyamides, polyphenylene oxide, high impact
polystyrene, polyether ketone, polysulfone, poly(phenylene
sulfide), acrylonitrile-butadiene, acrylic-styrene-acrylonitrile,
poly(ethylene terephthalate), poly(butylene terephthalate),
poly(ethelyne vinyl alcohol), poly(tetrafluoroethylene) and their
copolymers including functional comonomers and blends thereof.
Still further, the cover 11 is preferably comprised of a polyether
or polyester thermoplastic urethane, a thermoset polyurethane, a
low modulus ionomer such as acid-containing ethylene copolymer
ionomers, including E/X/Y copolymers where E is ethylene, X is an
acrylate or methacrylate-based softening comonomer present in 0-50
weight percent and Y is acrylic or methacrylic acid present in 5-35
weight percent. More preferably, the acrylic or methacrylic acid is
present in 15-35 weight percent, making the ionomer a high modulus
ionomer.
The mantle portion 16 is made of at least a first layer 20
surrounding the liquid or fluid filled cavity or center 18 and a
second mantle layer 22 surrounding the first mantle layer 20. The
first mantle layer 20 is preferably made of a thermoset rubber such
as polyisoprene, styrene butadiene, polybutadiene and combinations
thereof; a plastic, such as polypropylene; or a thermoplastic
elastomeric material such as copolymers of methyl-methacrylate with
butadiene and styrene, copolymers of methyl-acrylate with butadiene
and styrene, acrylonitrile styrene copolymers, polyether-ester,
polyether-amide, polyurethane and/or blends thereof. In another
embodiment, the first mantle layer 20 is made of a metallic
material, and is preferably a light weight metal such as
aluminum.
The mantle portion 16 also comprises the second layer 22
surrounding the first mantle layer 20. The second mantle layer 22
is shown as a single layer, but can be one or more layers made from
one or more materials. FIG. 1A shows the second mantle layer 22
having two layers 38 and 40. The second layer 22 is preferably made
of thermoset rubber such as polyisoprene, styrene butadiene,
polybutadiene and combinations thereof or thermoplastic elastomeric
materials such as copolymers of methyl-methacrylate with butadiene
and styrene, copolymers of methyl-acrylate with butadiene and
styrene, acrylonitrile styrene copolymers, polyether-ester,
polyether-amide, polyurethane and/or blends thereof.
The mantle portion 16 preferably has an outside diameter d3 in the
range of 80 to 98% of the finished ball diameter D and an inner
diameter d1 in the range of 30 to 70% of the finished ball
diameter. Preferably, mantle portion 16 and the first mantle layer
20 have an inner diameter of approximately 0.5 to 1.18 inches and,
more preferably, an inner diameter of approximately 0.75 to 1.1
inches. Preferably, the mantle portion 16 and first mantle layer 20
have an inner diameter of approximately 0.9 to 0.95 inches. The
second mantle layer 22 preferably has an inner diameter d2 in the
range of 0.55 to 1.45 inches and, more preferably, approximately
0.8 to 1.3 inches. Yet further still, the mantle portion 16 and the
second mantle layer 22 have an outside diameter in the range of 1.3
to 1.65 inches and, more preferably, approximately 1.45 to 1.62
inches. A golf ball incorporating these measurements can be
designed with the various attributes discussed below, such as
specific gravity, resiliency and hardness, to provide the desired
playing characteristics, such as spin rate and initial velocity.
More particularly, by using a first mantle layer to surround the
fluid or liquid center and at least a second mantle layer, the
specific gravities and other properties can be tailored to provide
optimum playing characteristics. More particularly, by constructing
a ball according to these dimensions, the second mantle layer is
made with a significant volume compared to the fluid center.
Preferably, the volume of the second mantle layer is greater than
the volume of the fluid center. More preferably, the volume of the
second layer is about 2 to 4 times the volume of the fluid center.
Thus, the properties of the second mantle layer can effect the
playing characteristics of the ball.
The hardness and resiliency of the mantle portion 16 can be varied
to achieve certain desired parameters such as spin rate,
compression and initial velocity.
Preferably, the mantle portion 16 has a hardness of approximately
30 to 95 Shore C, and more preferably, 45 to 90 Shore C. Still
further, the mantle portion 16 has a resiliency greater than 40
bashore.
In a most preferred embodiment, the first mantle layer 20 is
comprised of a plastic material having high temperature resistance.
The second mantle layer 22 is comprised of a polybutadiene material
that has high specific gravity for a low spin rate ball and a low
specific gravity for a high spin rate ball. It is known that the
specific gravity of the polybutadiene material can be varied by
adding fillers known to those skilled in the art.
The fluid cavity or center 18 can be filled with a wide variety of
materials including air, water solutions, gels, foams, hot-melts,
other fluid materials and combinations thereof. The fluid or liquid
in the center 18 can be varied to modify the performance parameters
of the ball, such as the moment of inertia. Preferably, the fluid
or liquid in the cavity 18 is comprised of a material that has a
high specific gravity for high spin rate golf balls and a material
that has a low specific gravity for a low spin rate golf ball.
Preferably, the specific gravity of the fluid or liquid is below or
equal to 1.2 for low specific gravity centers and above 1.2 for
high specific gravity centers. More preferably, the specific
gravity is approximately 1.15-1.2 for low specific gravity centers
and approximately 1.3-1.55 for high specific gravity centers. Still
further, the fluid is preferably comprised of a material with a low
viscosity for a golf ball having a high spin rate and a material
having a high viscosity for a golf ball having a low spin rate.
Preferably, the viscosity of the fluid or liquid center is less
than 100 cps for low viscosity centers and greater than or equal to
100 cps for high viscosity centers. More preferably, the viscosity
of the fluid or liquid center is less than or equal to 10 cps for
low viscosity centers and is between 100 and 1500 cps for high
viscosity centers. Most preferably, the fluid or liquid center
viscosity is approximately 500 cps for high viscosity centers.
Examples of suitable liquids include either solutions such as salt
in water, corn syrup, salt in water and corn syrup, glycol and
water or oils. The liquid can further include pastes, colloidal
suspensions, such as clay, barytes, carbon black in water or other
liquid, or salt in water/glycol mixtures. Examples of suitable gels
include water gelatin gels, hydrogels, water/methyl cellulose gels
and gels comprised of copolymer rubber based materials such a
styrene-butadiene-styrene rubber and paraffinic and/or naphthenic
oil. Examples of suitable melts include waxes and hot melts.
Hot-melts are materials which at or about normal room temperatures
are solid but at elevated temperatures become liquid. A high
melting temperature is desirable since the liquid core is heated to
high temperatures during the molding of the second mantle layer and
the cover.
The liquid in the cavity 18 can be a reactive liquid system which
combine to form a solid. Examples of suitable reactive liquids are
silicate gels, agar gels, peroxide cured polyester resins, two part
epoxy resin systems and peroxide cured liquid polybutadiene rubber
compositions. It is understood by one skilled in the art that other
reactive liquid systems can likewise be utilized depending on the
physical properties of the mantle layer and the physical properties
desired in the resulting finished golf balls.
The core 12 is preferably 60 to 95% of the total ball weight and
more preferably, 75 to 86% of the ball weight. As stated above, the
weight distribution within the core 12 can be varied to achieve
certain desired parameters such as spin rate, compression and
initial velocity.
For example, by increasing the diameter of the fluid or liquid
filled center cavity 18, and increasing the specific gravity of the
mantle portion 16, the weight distribution of the core is moved
toward the outer diameter for a lower spin rate ball. In contrast,
the diameter of the fluid or liquid filled center 18 can be
decreased and the specific gravity of the mantle layer 16 decreased
to move the weight distribution of the ball towards the ball center
for a high spin rate ball.
Similarly, the specific gravity of the fluid or liquid filled
center can be decreased and the specific gravity of the mantle
portion 16 increased for a low spin rate ball. Alternatively, the
specific gravity of the fluid or liquid filled center 18 can be
increased and the specific gravity of the mantle portion 16
decrease for a high spin rate ball.
Various examples of golf ball cores according to the invention are
set forth below.
EXAMPLE 1
A core according to the present invention was created having a
liquid center, a first mantle layer surrounding the liquid and a
second mantle layer surrounding the first mantle layer.
The liquid was a salt, water and corn syrup solution comprised of
40% salt, 30% water and 30% corn syrup. The liquid center had an
outside diameter of approximately 0.965 inches.
The first mantle layer was created from a thermoplastic elastomer.
The first mantle layer had an outside diameter of approximately
1.125 inches.
The second mantle layer was created from crosslinked polybutadiene.
The second mantle layer had an outside diameter of approximately
1.51 inches.
The core weighed 38.9 g and had a PGA compression of less than
60.
EXAMPLE 2
A core according to the present invention was created having a
liquid center, a first mantle layer surrounding the liquid and a
second mantle layer surrounding the first mantle layer.
The liquid was a salt, water and corn syrup solution comprised of
40% salt, 30% water and 30% corn syrup. The liquid filled center
had an outside diameter of approximately 0.938 inches.
The first mantle layer was created from polypropylene. The first
mantle layer had an outside diameter of approximately 1.0625
inches.
The second mantle layer was created from crosslinked polybutadiene.
The second mantle layer had an outside diameter of approximately
1.51 inches.
The core weighted 33.4 g and had a PGA compression of approximately
60.
EXAMPLE 3
A core according to the present invention was created having a
fluid center, a first mantle layer surrounding the fluid and a
second mantle layer surrounding the first mantle layer.
The fluid was air. The fluid center had an outside diameter of
approximately 0.938 inches.
The first mantle layer was created from polypropylene. The first
mantle layer had an outside diameter of approximately 1.0625
inches.
The second mantle layer was created from crosslinked polybutadiene.
The second mantle layer had an outside diameter of approximately
1.51 inches.
The core weighted 26 g and had a PGA compression of approximately
87.
Turning to FIGS. 2 and 3, a golf ball of the present invention can
be formed by initially forming the first mantle layer 20 to create
cavity or center 18 and filling the cavity 18 with fluid or liquid.
The second mantle layer is formed by pre-forming top and bottom
cups 30 and 31 of polybutadiene in a compression mold 32 with an
inner fixture 34 as shown in FIG. 2. The mold 32 is then opened and
the inner fixture 34 is removed, leaving a preform 36 in the top
and bottom cups 30 and 31 of the second mantle layer. The first
mantle layer 20 and fluid or liquid center 18 are then inserted
into the bottom cup 31 and the mold 32 is closed and run through a
normal temperature and pressure cycle to crosslink the second
mantle layer 22 to form the core 12. The cover 11 is then
compression molded or injection molded over the core 12, which
processes are well known in the art.
While it is apparent that the illustrative embodiments of the
invention herein disclosed fulfills the objectives stated above, it
will be appreciated that numerous modifications and other
embodiments may be devised by those skilled in the art. Therefore,
it will be understood that the appended claims are intended to
cover all such modifications and embodiments which come within the
spirit and scope of the present invention.
* * * * *